Combined control means for adjusting aperture size and shutter speed of cameras



April 18, 1950 M. N. FAIRBANK 2,504,312

\ cousnmn CONTROL MEANS FOR ADJUSTING APERTURE SIZE AND SHUTTER SPEED OFCAMERAS Original Filed Feb. 7, 1947 3 Sheets-Sheet l INVENTOR Ki/t 'ewaApnl 18, 1950 FAlRBANK 2,504,312

COMBINED CONTROL MEANS FOR UST G APERTURE SIZE AND SHUTTER SPEE F C RASOriginal Filed Feb. 7, 1947 '3 Sheets-Sheet 2 INVENTOR P" 18, 1950 M. N.FAIRBANK 2,504,312

COMBINED CONTROL MEANS FOR ADJUSTING APER'IURE SIZE AND SHUTTER SPEED QFCAMERAS Original Filed Feb. 7, 1947 3 Sheets-Sheet 5 INVENTOR PatentedApr. 18, 1950 COMBINED CONTROL MEANS FOR ADJUST- ING APERTURE SIZE ANDSHUTTER SPEED OF CAMERAS Murry N. Fairbank, Belmont, Mass., assignor toPolaroid Corporation, Cambridge, Mass, a corporation of DelawareOriginal application February 7, 1947, Serial No. 727,002. Divided andthis application January 25, 1949, Serial No. 72,665

11 Claims. 1

This invention relates to photographic apparatus and more particularlyto novel shutter and diaphragm mechanism and indicating means therefor,for association with the exposure aperture of a camera.

This application is a division of application Serial No. 727,002, filedFebruary 7, 1947, by Murry N. Fairbank and Sidney B. Whittier for Camerashutter mechanism.

An object of the invention is to provide camera shutter and diaphragmelements having associated therewith novel mechanism and indicatingmeans providing an operational setting of said elements to a givenexposure value, said operational setting comprising shutter speed anddiaphragm aperture settings selectable from a plurality of availablesettings thereof whereby a correct photographic exposure may beobtained.

A further object of the invention is to provide camera shutter anddiaphragm elements having associated therewith novel mechanism,indicating means, and control means for setting up a given exposurevalue from a plurality of selectable exposure values, the aforesaidmechanism, indicating means, and control means coacting to assuremaximum possible shutter speed at any aperture setting.

Still another object of the invention is to provide simple indicatingand control means connecting with mechanism for setting up camerashutter speeds and aperture diameters suitable for employment with oneanother for obtaining correct photographic exposures, the indicatingmeans comprising a rotatable dial element having placed thereupon aplurality of numbers in progressive order representing a plurality ofpreestablished light values, and a fixed index element, said dial beingrotatable through a. single control knob, enabling said dial numbers tobe brought adjacent said index, thereby setting up a shutter speed andan aperture diameter suitable for providing a given exposure.

A still further object of the invention is to provide means for varyingshutter speed and size of diaphragm apertures, said means being combinedin a single rotatable element.

Yet another object of the invention is to provide a fixed index and asingle rotatable element for varying both shutter speed and size ofdiaphragm apertures, said rotatable element also carrying light valueindicia selectively positionable relative to said fixed index.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts which areexemplified in the following detailed disclosure, and the scope of theapplication of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings wherein:

Figure 1 is a somewhat schematic elevational view, partly in crosssection and with parts broken away, of one form of the novel apparatusof the invention;

Fig. 2 is a fragmentary elevational view of a modification of shutterspeed setting elements of Fig.

Fig. 3 is a somewhat schematic elevational View of a furthermodification of mechanism of Fig. 1 incorporating a single control forobtaining correlated settings of the shutter and diaphragm;

Fig. 4 is a fragmentary perspective view of elements of Fig. 3illustrating operation thereof; and

Fig. 5 is a schematic elevational view of a preferred modification ofmechanism incorporating a single control for obtaining correlatedsettings of the shutter and diaphragm.

Shutter mechanism of the general form comprehended by the invention isrelatively simple in construction and possesses accurate timekeepingproperties, due in large measure to novel constructions providing aminimum of surfaces in frictional contact with one another duringmovement of the shutter. A shutter of the aforesaid characteristicspermits accurate calibration of its various speed settings and will beseen to have advantages wherein a large measure of control of thefinished print may depend upon exposure values. Shutter speed, asreferred to herein, is to be regarded in terms of an exposure periodduring which light passes through the lens aperture. The exposure periodis determined by the size of the are through which the shutter rotatesbefore reversal of its movement takes place and to controlled speed ofmovement thereof, to and from a point of reversal. The shutter isadapted to incorporation with any of a variety of conventional camerasbut is particularly suitable as a between-the-lens shutter in camerasemploying lenses of small relative aperture which are adapted toexposure of film having a fast emulsion. A rotatable disc-type diaphragmhaving a plurality of apertures of predetermined diameter may preferablybe employed in conjunction with the shutter, said type of diaphragmpermitting formation therein of small apertures of exact light admittingproperties and, as exemplified by the invention, being particularlysuitable for actuating shutter speed setting elements directly orthrough interlocking mechanism. An iris type diaphragm may, however, beemployed satisfactorily with the aforesaid shutter. Indicating meansshown, while particularly adapted to association with the novel shutterand diaphragm of the invention, may be used in conjunction with othertypes of shutters and diaphragms through provision of suitableinterconnecting mechanism.

Referring to Fig. 1, the rotatable shutter blade l2, shutter bladecounterbalance l4, fragmentary portion of the disc-type diaphragm l6,and other associated elements are represented as they would appear froma position in front of a camera, casing portions, excepting a smallsection [8 thereof, having been broken away for the purpose of exposingthe aforesaid elements. For convenience of terminology, the shutterblade 12, counterbalance l4, hub 20, and bearing shaft or axle 22 mayoccasionally be referred to herein as the shutter, all of theaforementioned elements being shown as rigidly attached to one anotherand thus rotatable as a unit. Directions of rotation of the shutter andother associated elements, and position of elements, as hereinafterdescribed, are those which would be observed when said elements areviewed from the above-described position, the descriptive language beingin accordance with said point of observation.

Shaft 22 is journaled at each extremity into bearing means 24 which maybe formed in a pair of rigid supporting members, one of said members 26being shown. Each of said supporting members between which the shutteris positioned, and upon which it is rotatably mounted by said bearingmeans, may alternatively be provided in the form of a web, or a portionof the camera casing per se. The shutter is shown in closed position,namely, shutter blade l 2 is positioned to obstruct the passage of lightthrough lens aperture 28. The aforesaid closed position of the shutteris determined by a limit stop comprising a magnet 30, against which ablock of suitable magnetic material 32, comprising an extremity ofcounterbalance I4, is brought to rest. Said magnet, preferably of ahorseshoe type, as shown, is bonded to a block composed of suitableresilient material 34, such as rubber or a material'com prisingpolyvinyl butyral, said block 34, in turn, being bonded to forwardlyextending portion 36 of an angular plate comprising also a lateralportion 36a with which said magnet is in slidable contact. A pin 38,preferably of nonmagnetic material, extends forwardly from plate 38,said pin being interposed between the poles of magnet 30 and having adiameter less than the distance between said poles. The aforesaidconstructions provide a limit stop which yields under impact of magneticblock 32. The magnet 30 of said limit stop coacting with magnetic block32 comprises means for preventing rebound of the shutter away from thestop once contact of said block 32 and magnet 30 has been established,magnetic force exerted upon said block by magnet 35 being adapted to thepurpose. It will be seen that said elements also hold the shutter atclosed position when idle. Movement of slidable magnet 30 toward block32 is limited by pin 38.

Projecting lug 40 of the counterbalance constitutes a portion of theshutter suitable for re- 4 ceiving an impulse for rotating said shutterin a. clockwise direction, more specifically, the righthand surface 46aof said lug being adapted thereto. In addition to providing meansagainst which a force for rotation may be applied, lu 40 serves ascontributory means for determining direction and extent of rotation ofthe shutter in the following manner. The extent of clockwise rotation ofthe shutter, when actuated for said movement by means more fully to bedescribed, is limited by contact of lug 43 with a spring 42, which maybe termed a rebound spring, mounted so as to intercept surface 4% of lugtil during arcual movement of the latter. Reversing means 42 may beconstructed of any suitably resilient material properly formed for thepurpose, said means preferably comprising a spring-like member composedof steel, phosphor bronze or the like. The spring may be flat in form,as shown, or of any other suitable shape and thickness forpredeterminedly limiting clockwise rotation of the shutter and forcausing rotational reversal of said shutter in a counterclockwisedirection. Thus, it will be seen that the measure of clockwiserotational movement of the shutter, from the closed position shown inFig. l, is determined by the arcual distance initially separating lug 40and spring 42, by the mass and velocity of the rotating shutter, and bythe deflection characteristics of spring 42 under load caused byimpingement of lug 48 thereupon. Further, it will be apparent that thespeed of rotation of the shutter through a single exposure cycle,comprising successive clockwise and counterclockwise rotation, issubstantially predetermined by such factors as the magnitude andcharacteristics of delivery of the force applied to lug so forinitiating its clockwise rotation, by the mass of the shutter by thedeflective characteristics of spring 42 and by the amount of frictionexisting between bearing members 22 and 24.

As shown in Fig. 1, rebound spring 42 may, for example, be mounted uponan annular spring carrier member 44, said carrier member being integralwith or suitably connected, as b members 46, to a hub 48, and said hubbeing rotatably mounted upon a fixed axle 5B. Axle 5% may preferably bein the form of an annular member rigidly attached to or integral withthe further supporting members 28, axle 59 and shaft 22 beingconcentric, and shaft 22 turning freely Within said fixed axle 59. Itwill be apparent from Fig. 1 that clockwise rotation of spring carriermember 44 for the purpose of altering the position of rebound spring 42increases the arcual distance which lug 49 must travel to and fromcontact with said rebound spring and hence decreases the shutter speed.Upon suitable =portions of its surface, such as the inner surface shown,spring carrier 44 is provided with predeterminedly spaced recesses 52adapted to releasable engagement with any suitable detent means, such asdetent means 54, whereby rebound spring 42 may be rotated to, andoperationally held at, any of a plurality of pre-established positions.In Fig. l, the position of elements shown represents a setting ofrebound spring e2 for maximum shutter speed, namely, a setting at whichlug 40 will travel a minimum arcual distance to said rebound spring andduring which shutter blade l2 will barely uncover aperture 28 prior tobeing reversed in its direction of rotation. At said position ofelements it will be noted that detent 54 engages recess 52a, thusinsuring a positive setting of said elements. Limit stops 56 and 58,fixedly mounted upon casing portions (not shown), are suitablypositioned for intercepting a pin 50 extending from spring carriermember 44 and for defining maximum counterclockwise and clockwiserotation, respectively, of Said member 44, said limits of rotation beingthose at which maximum and minimum shutter speed, respectively, occur.

Means suitable for manually rotating rebound spring carrier member 44,and thereby varying shutter speed, as above described, are provided,respectively, by a toothed construction of peripheral portions of saidmember 44 forming a gear 62, by a pinion 64 engaging said gear 62, andby a control knob 66, rigidly attached to said pinion 64, through ashaft 68, said shaft being of a length sufficient to extend through thecamera casing and permit manual rotation of said knob exteriorly of saidcasing.

As previously stated, any conventional diaphragm may be operationallyassociated with the shutter of the invention, a disc-type diaphragmbeing particularly suitable where simplicity of construction and smallrelative apertures are to be employed. The disc-type diaphragm I8, shownin fragmentary form in Fig. l, is mounted for rotation about a fixedaxle 10, said axle being, for example, in the form of an annular memberrigidly attached to or integral with supporting member 26, andconcentric with shaft 22, it being assumed that the diaphragm comprisessuitable hub portions (not shown) for mounting upon axle 10. Meanssuitable for rotating the diaphragm and for centering any of theapertures thereof adjacent lens aperture 28 are provided, said means,for example, comprising a toothed construction of peripheral portions ofdiaphragm I6 forming a gear I2, a pinion I4 engaging said gear I2, and acontrol knob 16 rigidly attached to said pinion I4 by a shaft I8 ofsuificient length to pass through the camera casing. The smallest ofavailable diaphragm apertures 80 is shown positioned contiguous lensaperture 28. Means for releasably holding any of the apertures ofdiaphragm I6 at exposure position comprise an annular flange portion 82of said diaphragm having a plurality of predeterminedly spaced recesses84 formed therein, said recesses being adapted to releasable engagementwith suitable detent means 85. provided for defining limits of rotationof diaphragm I6, stop limit 88, mounted on casing or frame portions ofthe camera (not shown), and pin 89. extending from said diaphragm, beingshown in contact therewith and representing a setting of extremecounterclockwise rotation of the diaphragm. Although not shown, it willbe understood that suitable indicating means may be incorporated withthe aforesaid mechanism whereby correlated settings of shutter speed andapertures are made in accordance with prevailing light values.

Self-cocking mechanism for actuating rotation of the shutter is shown inelevation in Fig. 1, the position of elements representing substantiallythat which would prevail at the instant when the shutter is about tocommence a given exposure cycle. The element of said mechanism whichcontacts the shutter directly is shown as a pivotally mounted arm 90which may be termed the impulse arm, said arm being biased forcounterclockwise rotation by an extension spring 92 attached,respectively, to said arm and to camera frame portions. An extremity ofimpulse arm 90 is held in contact with lug 40 of the shutter, at

Suitable stop limits may be cocked position of the shutter actuatingmechanism, and is adapted to transmit driving force to said lug for abrief period upon release of said shutter actuating mechanism. Uponreception of driving force from arm 90, the shutter commences to rotatethrough an exposure cycle. It will be seen in the aforesaid relation ofelements that counterclockwise rotation of impulse arm causes clockwiserotation of the shutter, rotational force being continuously transmittedby said impulse arm to shutter lug 40 until divergence in the arcualmovement of said shutter and impulse arm, due to separate pivotal mountings thereof, breaks their contact with one another. Under impetusinitially supplied by said impulse arm 90, the shutter continues torotate in a clockwise direction until it impinges rebound spring 42 andits direction of rotation is reversed thereby, as previously described.A shoulder 93 or other suitably formed portion of arm is provided forengagement with a latch 94, said latch having a notched portion 94a forthe purpose, and said latch being rotatably mounted upon a portion ofthe camera frame (not shown) by a pivot 96 and biased toward saidshoulder by a spring 98. Counterclockwise rotation of latch 94 islimited by limit stop I00 mounted upon aforesaid camera frame. Impulsearm 90, after terminating its contact with lug 40, continues to rotatein a counterclockwise direction under bias applied by spring 98 untilmeeting limit stop I02. As shown, liimt stop I02 is in the form of apair of spring-like elements, comprising a pair of electrical contacts,said elements providing effective cushioning means for terminatingpivotal movement of impulse arm 90 and for completing a circuit to aphotoflash lamp (not shown). It will be understood that element 102 mayserve as a limit stop only, where no connection to a photofiash lamp isprovided.

It will be noted that impulse arm 90 constitutes one arm of a bell-crankwhich comprises a second arm I04 extending angularly relative to arm 90,said arm I04 being adapted, during cooking of the mechanism, to receivea rotational force, which will presently be described, causing itspivotal movement in a clockwise direction and thus returning impulse arm90 to a cocked position. The bell-crank, comprising arms 90 and I04, isrotatably connected by pivot I05 to an arm I08, said last-named arm, inturn, being rotatably connected by pivotal stud IIO to trigger II2. StudI I0 is of sufficient length to provide a clearance between arm Hi8 andtrigger H2 for unobstructed movement therebetween of the bellcrankcomprising arms 90 and I04. It should be noted that arm I08, during thecooked position of impulse arm 90, shown, is at an angle ofcounterclockwise rotation which brings it adjacent limit stop I14comprising a pin mounted upon a portion of the camera frame, extensionspring 92 operating to bias arm I08 toward said stop in addition to itsfunction of actuating impulse arm 90 as hereinbefore described. TriggerH2, in turn, is rotatably mounted upon a frame portion by an inwardlyextending portion of the aforesaid pivot IIO, it being understood thatindependent rotation is permitted elements I08 and H2. Trigger H2comprises a handle portion H6 extending through slot H8 in casing I8,said portion being adapted to manual movement for rotating the triggerhandle in a counterclockwise direction to limit stop l20, said stop, asshown, being formed by a portion of casing I8. Upon release of handleIE5, clockwise rotation of trigger II2, comprising said handle,- isactuated through bias applied thereto by extension spring I 22,connected, respectively, to said handle H6 and a frame or casing portionof the camera.

Trigger I I2 also comprises an angular arm portion I24 suitably formedfor both tripping and cocking the aforesaid mechanism for actuatingrotation of the shutter. When trigger handle I I6 is manually rotated ina counterclockwise direction, arm I24 is caused to rotate similarly andsurface I24c of said arm is actuated to move substantially upwardly tocontact latch 94, and to withdraw said latch from shoulder 93 of impulsearm 90, thus releasing the impulse arm and enabling the latter to drivethe shutter. In Fig. l trigger portion I24a is shown actuating latch 94in the above-described manner. It will be apparent that when impulse arm90 is rotated in a counterclockwise direction to its limit stop I02, armI04, integral therewith, is rotated in a similar direction to a positiongenerally adjacent surface I24b of arm I24. Upon removal of manual forcefrom trigger handle H6, extension spring I22 assumes control of themechanism, trigger II2, comprising handle H6 and arm portion I24, beingcaused to rotate in a clockwise direction. Latch 94 rotates to its limitstop I00, and surface I24b is brought to bear upon arm I04. Therotational force applied by said surface I24b to arm I04 accomplishestwo functions relative to cocking the mechanism, said functions beingperformed substantially concurrently, as follows. Assuming tension ofspring I22 to exceed that of spring 92, as indicated in the drawing, armI08 is caused to rotate in a clockwise direction about pivotal stud II0, impulse arm 90, accordingly, being rotationally carried in agenerally downward direction to a position enabling its extremity topass freely beneath shutter lug 40 during return rotation of the impulsearm to cocked position. During the aforesaid rotation of the impulse armto cocked position, shoulder 93 moves along angular surface 940 of latch94, thereby rotationally lifting the latch slightly against the bias oflatch spring 98, said shoulder finally entering notch 94a of said latch.Clockwise rotation of arm I and trigger II2, upon completion ofaforesaid operations, is limited by stops I26 and I28, respectively.

Mechanism adapted to manual setting for a bulb exposure and havingassociated therewith means providing automatic return of said mechanismto an instantaneous exposure setting, after completion of the bulbexposure is shown in Fig. 1, said associated means comprisinginterlocking connection with the trigger, for achieving said automaticreturn. The aforesaid mechanism and associated means com-prise latchingarm I30 mounted upon a bell-crank I32, said bell-crank, in turn, beingrotatably mounted upon frame portions of the camera by a pivot I34. Whenarm I30 is pivoted to maximum clockwise or bulb exposure position,extreme portions thereof are brushed aside by lug 40 during clockwiserotation of the latter. After lug 40 has passed latching arm I30, saidarm springs inwardly, lug surface 40b strikes rebound spring 42, thelatter reverses the direction of shutter rotation, and the tip oflatching arm I 30 intercepts surface 40a of said lug, terminatingfurther rotation of the shutter and holding the shutter at openposition. It will be understood that deflection characteristics oflatching arm I30 are such as to permit no appreciable diminution inspeed of clockwise rotation of the shutter, thus insuring accurate timeexposures. The shutter is biased against latching arm I30 by torsionalhairspring I36 connected respectively to rotatable shutter shaft 22 andsupporting member 25. The hairspring has substantially no effect uponoverall shutter speed during a given rotational cycle of the shutterinasmuch as said hairspring, while retarding shutter rotation in aclockwise direction, accelerates rotation of the shutter in acounterclockwise direction, one force substantially canceling the otherduring the complete shutter cycle. Means for rotating shutter latchingarm I30 in a clockwise direction comprises a lever-like stud I38extending angularly from modified bell-crank I32 and a horizontallymovable arm I40 extending through casing I8, said arm having a controlknob I42 attached thereto at an extremity exterior of said casing andhaving a slot I44 formed therein for receiving said stud I38. It will beapparent that manual actuation of arm I40 causes pivotal movement ofbell-crank I32 and latching arm I30 extending therefrom. In Fig. 1, armI40 is shown at its maximum inward position, namely, at a position forinstantaneous exposure, as determined by contact of knob I42 with casingI8, said arm I40 having rotated shutter latching arm I30 in acounterclockwise di-' rection outside of the arcual path of lug 40.Suitable detent means are provided for releasably holding the aforesaidelements in positions shown, said means comprising a spring member I46mounted on guide I48 and adapted to en- :gage a recess I50 formed in armI40, guide I48 being mounted upon frame portions of the camera. A dogI52 extending perpendicularly from arm I40 is provided for contactingcasing I8 during withdrawal of said arm through said casing, therebyfixing the limit of said withdrawal ,and, accordingly, establishing thelimit of clockwise rotation of shutter latching arm I30 which provides abulb exposure setting.

Interlocking mechanism for automatically re turning arm I40 inwardly andthereby rotating shutter latching arm I30 in a counterclockwisedirection for releasing lug 40, after a bulb exposure, comprises an armI54 rotatably mounted upon an extremity of trigger II2 by pivot I56, aspring I58 biasing arm I54 in a counterclockwise direction, extremityI40a of arm I40, suitably formed for slidable contact of arm I54therewith,

and arm I60 of modified bell-crank I32. With arm I40 at the maximuminward or instantaneous exposure position shown in Fig. l, pivotalmovement of the trigger causes no movement of latching arm I30, edgeportion I54a of arm I54 being adapted to slide freely upon edge surfaceI40a of arm I40. When the trigger is at full cocked position, asdetermined by contact thereof with limit stop I28, said edge portionI54a is brought to rest against surface portion I60a of arm I60. Itfollows that portion I54a still bears upon portion I6I|a when arm I40 iswithdrawn to its limit for a bulb exposure, said withdrawal causingclockwise rotation of arm I60. Assuming the last-named setting ofelements and the trigger to be manually actuated in a counterclockwisedirection, surface I54a is slidably removed from surface IBM, and armI54 is caused to rotate in a counterclockwise direction, under bias ofspring I58, the extremity thereof, I54b, passing beneath arm I60, theangle of rotation of said arm I54 being small owing to renewed contactof surfaces I54a and I40a. After removal of manually applied force fromhandle I I6, the trigger is actuated by extension spring I22,

said trigger being rotated in a clockwise direction and returned to afull cocked position. Coincidental with said last-named return rotationof the trigger, extremity I54b of arm I54 moves substantially upwardly,bears against surface I601) of arm I60, and rotates said arm I60 in acounterclockwise direction. Accordingly, said counterclockwise rotationof arm I60 pivots latching arm I30 similarly to instantaneous exposureposition by drawing arm I40 to its maximum inward position. Ashereinbefore described, when latching arm I30 is pivoted in acounterclockwise direction to instantaneous setting, torsionalhairspring I36 returns the shutter to closed position. In rsum and inaccordance with the aforesaid constructions and operation of elements,it will be seen that a bulb exposure is obtained by withdrawing knob I42to the limit stop, and by manually actuating the trigger, the period ofsaid exposure being determined by the time during which the triggerhandle is manually depressed against stop I20. After release of thetrigger handle, the impulse arm is automatically recooked, the shutterreturns to ciosed position, and the mechanism is reset for aninstantaneous exposure.

In Fig. 2, alternate means for varying shutter speed are shown, saidmeans comprising a plurality of rebound or shutter reversing springs,each of said springs being functionally similar to the single spring ofFig. 1 and enabling reversal of rotation of the shutter at apredetermined angle thereof. The rebound springs have suitable mountingand actuating means associated therewith enabling their selectivepositioning in the path of shutter rotation, each spring, when thuspositioned, being capable of providing a predetermined shutter speed.The mechanism of Fig. 2 is adapted to incorporation with the shutter,shutter actuating mechanism, bulb exposure," and instantaneous exposureelements of Fig. 1. Two such rebound springs I62 and I64 areillustrated, it being understood that additional rebound springs may beprovided, said springs being spaced apart at predetermined intervalsaround the path of arcual movement of the shutter. The rebound springsare mounted upon individually positionable arms I66 and I68, said armsbeing adapted to provide movement of the rebound springs in and out ofthe path of shutter rotation. Arms I66 and I68 are rotatably mountedupon portions of the camera casing or frame (not shown) by pivots I andH2, respectively, said arms comprising cam followers I14 and I16. Thecam followers are adapted to actuation by cam I'I8 which is carried bygear I00, said gear, in turn, being rotatable by pinion I82, having knobI84 afiixed thereto. Arms I66 and I68 are biased inwardly by springs I86and I88, limits of inward or clockwise rotation of said arms beingestablished by stops I90 and I82, respectively. When cam H8 is rotated,for example, in a clockwise direction it will be seen that cam followerI14 is actuated, causing counterclockwise rotation of arm I66 andremoval of rebound spring I62 from the path of shutter rotation, thusleaving rebound spring I64 in functional position. Suitable detentmeans, such as means shown in Fig. 1, are provided for positivelydesignating and releasably holding each rebound spring at functionalposition. Further rotation 01' cam I18 removes rebound spring I64 fromthe shutter path, thus permitting additional rebound springs (not shown)to assume the function of shutter reversal. It is to be understood that10 springs I86 and I88 are of sufficient stifiness to hold arms I andI68 firmly against their respective stops when the shutter strikes therebound springs.

Figs. 3 and 4 comprising elevational and perspective views of onemechanism show shutter speed and diaphragm control elements which aresomewhat similar in form to those represented in Fig. 1 insofar as saidmechanism embodies a single rebound spring IBI, a rebound spring carrier93, a disc-type diaphragm I94, and detent means I96 and I98 mounted uponfixed bracket of frame portions (not shown) and adapted to engagerecesses 200 and 204 formed in said carrier and diaphragm, respectively,as for example, in suitable annular flanges 206 and 208, for reieasablyholding the rebound spring and diaphragm at various angles of rotationthereof. The assembly, howevercomprises modified means for achievingcorrelated settings of the rebound spring and diaphragm apertures, and,furthermore, comprises indicating means for establishing said settings.The rebound spring carrier and diaphragm are represented asnonconcentric, principally to enable a clear showing of theconstructions, concentric mounting of said elements being readilypossible, however, without affecting operation thereof. It is to beassumed that suitable bearing means, such as those shown in Fig. 1, areprovided for rotational mounting of said elements in a camera.

Rebound spring carrier I83 comprises toothed peripheral portions forminggear 2I0, a lug 2I 2 mounted to extend substantially radially upon saidcarrier, and toothless sector 2 I4 interrupting continuity of gear 2 I0.Diaphragm I94 comprises a plurality of apertures 2I6 of predeterminedlyvarying diameter formed therein, toothed peripheral portions forminggear 2 I8, a lug 220 extending substantially radially from the peripherythereof, and toothless sector 222 interrupting continuity of gear 2 I8.A yoke-like element 224, comprising bearing shaft 226 and arms 228 and230 is pivotaliy mounted upon casing or frame portions (not shown), saidyoke, in conjunction with the aforesaid lugs. serving as a medium forthe transmittal of rotational force from the diaphragm gear 2I8 to therebound spring gear 2H: and vice versa. Said yoke is preferably gentlybiased in a clock wise direction against stop 23I byspring 232. A pinion234 is adapted to engage gears 2H! and 2 I8, said pinion having acontrol knob 236 rigidly connected thereto by a shaft 230, said shaftpassing through a suitable bearing in the camera casing (not shown). Theconstructions and mutual operation of aforesaid gears 2|!) and 2I8, lugs2I2 and 22 toothless sectors ZI-i and 222, yoke 224, and pinion 234 aresuch that when one of said toothless sectors has been rotated to a.position adjacent pinion 234 the element of which it forms a partderives no rotational force and remains stationary while the elementcomprising the other toothless sector is adapted to rotation, throughengagement of its toothed peripheral portions with said pinion 23. Asshown in Fig. 3, toothless sector 222 of the diaphragm is adjacentpinion 23d and, accordingly, the diaphragm remains stationary, thelargest aperture thereof being adjacent the exposure aperture However,peripheral gear 2I0 of the rebound spring carrier is in engagement withsaid pinion 23 enabling variation of position of the rebound spring andhence variation of shutter speed. In Fig. 3, it is also to be noted thatrebound spring I92 is at maximum clockwise position, providing slowestshutter 11 speed, said position being established by contact of. lug 212with limit stop 242.

Fig. 4 illustrates clockwise rotation of pinion 234 and the transfer ofcounterclockwise rotational force from the rebound spring carrier to thediaphragm through the media of the aforesaid lugs and yoke. Toothlesssector 214 has been rotated adjacent pinion 234. Lug 212 has actuatedyoke arm 239 in a clockwise direction, causing similar rotation of yokearm 223. Arm 223 has actuated lug 226 in a counterclockwise directionremoving toothless sector 222 from adjacency with pinion 234 and causingengagement of gear 2I8 with said pinion. During transfer of rotationalforce, gears 219 and 2 l8 will both be caused to rotate for a briefperiod. During said simultaneous rotation the largest aperture is eitherbrought to the exposure position or removed therefrom depending upon thedirection of rotation of the aforesaid elements. With any aperture otherthan the largest at operating position, recess 200 is engaged withdetent I96, giving maximum possible shutter speed. During simultaneousrotation of diaphragm I94 and carrier I93, recess 200a is moved intoengagement with detent 196. The maximum shutter speed obtainable withthe largest aperture in position is thus slightly less than the maximumspeed for other apertures.

Indicating means of Figs. 3 and 4 comprises rotatable dial 244 and fixedindex 246, said dial carrying a plurality of numbers, arranged as shown,said numbers representing light values. Said light values may preferablycorrespond to light value numbers carried on the scale of a light meter,thus permitting a setting of the a indicating means directly, accordingto the prevailing value indicated on the light meter, without thenecessity of first computing a correct setting. Rotation of dial 244 tobring a given number thereof adjacent index 2&6 sets up a correlatedshutter speed and diaphragm aperture providing a predetermined exposurevalue, said rotation of the dial being accomplished by a gear trainconnecting said dial with pinion 234 and comprising gears 248, 259, 252,and 254. It is to be understood that said gears and gears 2H] and 218are of suitable relative diameter and that gears 248, 216, and 218 areengaged at suitable angles of rotation for insuring dial settings whichare accompanied by accurate exposure value settings of the mechanism.Assuming the lowest number to indicate an extremely low light value, aprevailing light value of very low intensity is indicated in the dialsetting of Fig. 3, showing number 1 at the fixed index, the largestdiaphragm aperture thus being positioned at the exposure aperture andthe rebound spring being at a position for eifecting slowest shutterspeed. Subsequent rotation of dial 244 in a clockwise direction to bringnumbers 2 through 6 to the fixed index provides progressive increases inshutter speed. Continued rotation of the dial provides positioning ofdiaphragm apertures of diminishing diameter at the exposure aperture,one complete rotation of the dial accompanying the entire range ofpossible rebound spring and aperture settings. The dial setting of Fig.4 indicates a transitional phase of exposure value settings whereat therebound spring is positioned for maximum shutter speed and the next tolargest diaphragm aperture is approaching the exposure aperture.

Fig. schematically represents a further modification of apparatuscomprising rotatable, disctype diaphragm 256 havin apertures 256 ofvarious diameter formed therein, rebound springs 26D,

262 and 264 for providing various shutter speeds, indicating meanscomprising numbers 2 to 14 inclusive, carried on a surface of thediaphragm, an aperture 266 in casing portion 268 through which saidnumbers may be individually observed. Said modification exemplifies asimplified and preferred design for settin shutter speed at a selectedpredetermined value and for bringing diaphragm apertures to exposureposition in fullstop steps, as, for example, fvl, fzSZ, f :22, f :16,and f :11 at /60 of a second, and for setting an aperture ofpredetermined diameter at the exposure aperture 219 and altering shutterspeed as, for example, fzll at /12 and /7 of asecond. The aforesaidnumbers represent light values as hereinbefore described, and aperture26% serves as a fixed index for positioning said numbers, any numbervisible therethrough being indicative both of that aperture which ispositioned adjacent exposure aperture 219 and of operational positioningof one of the aforesaid rebound springs. It is to be understood thatelements of Fig. 5 are viewed from a position similar to that assumed inFig. 1 and that a shutter of the general type shown in Fig. 1 is to beassociated therewith, said shutter thus rotating in a clockwisedirection, meeting one of the rebound springs, and returning to originalposition. Any combination of settings of the aforesaid mechanism,obtained by bringing a selected number to aperture 266, provides acorrect exposure value.

A pinion 212 and control knob 214, unitary therewith and positionableexteriorly of a camera casing, provide means for rotating diaphragm256," said pinion engaging gear portion 216 of the diaphragm foractuating said gear. Rebound springs 266 and 262 are mounted,respectively, upon rotatable arms 218 and 286, said arms rotating aboutrespective pivots 282 and 264 and being biased for clockwise rotation bysprings 286 and 288. The aforesaid elements are mounted upon suitableframe or casing portions (not shown). Each of said arms also comprises,respectively, a cam follower 290 and 292, said followers being adaptedto ride on the periphery of the diaphragm and said periphery being inthe form of a cam. Said cam comprises two sectors 294 and 296, sector296 having a greater radius than sector 294. When the diaphragm isrotated and followers 290 and/or 292 ride upon sector 296, reboundsprings associated therewith are rotated substantially radially awayfrom the arcual path of the shutter to nonoperational position, and whensaid followers ride upon sector 294, they are functionally positionedfor intercepting said shutter during rotation thereof. Again consideringinitial clockwise rotation of the shutter,

as shown in Fig. 1, it will be seen from Fig. 5 that rebound spring 264is the last of said springs for intercepting the shutter and, becausesaid spring 264 provides the slowest shutter speed, it may be fixedlymounted, as shown. Suitable detent means are provided for releasablyholding the diaphragm at various rotational positions identified withthe positioning of each of the several apertures adjacent lens aperture216. Said means comprises, for example, fixed axle 296, detent means 306suitably mounted therewithin, and a plurality of recesses 302 formed indiaphragm hub 364 and adapted to engage said detent,

Although it will be understood that the number of rebound springs shownis not arbitrary and that rebound springs having suitable positioningmeans therefor may be deleted or added according to the number ofshutter speeds to be included, the

length of cam sector 296 and positionin of respective followers must becarefully predetermined for moving rebound springs in and out ofposition. At the setting of mechanism shown in Fig. 5, cam sector 296has raised cam followers 299 and 292, causing rotation of reboundsprings 260 and 262 to idle position, fixed rebound spring 264 beingoperative for providing a shutter speed of /7 of a second.Counter-clockwise rotation of the diaphragm from said settingprogressively causes the cam followers to leave sector 296 and bear uponsector 294, in turn, bringing rebound springs 262 and 260 intofunctional position, thus providing respective shutter speeds of and /60of a second. For obtaining a shutter speed of /60 of a second whenaperture fzll is positioned adjacent lens aperture 210 it will beobvious that cam sector 296 should not actuate cam follower 296, saidcondition being rendered possible by a sufiiciently limited length ofsaid cam sector 296. A suitable length of cam sector 296 is insured byforming arm 290, between cam follower and rebound spring mountingportions thereof, of a sufficient length for the purpose. Springs 296and 288, respectively, provide means for holding'cam followers 290 and292 in contact with cam sector 294 whereby impact of the shutter againstrebound spring 260 or 262 causes no radial displacement of said reboundsprings. It will be understood that the diaphragm may be rotated ineither clockwise or counterclockwise direction for obtaining any of theaforesaid settings with utmost rapidity and that detent 300 engagingrecesses 302 operates to hold the diaphragm stationary when numericalindicia are positioned adjacent the fixed index. It is further to beunderstood that f: and time values shown in Fig. are illustrative andnot to be considered as arbitrary values.

Mechanisms schematically shown in the drawings include a plurality ofelements which are generally suitable in form for performing variousabove-described functions. However, it will be evident that certain ofsaid elements may readily be altered in form, or interchanged to formfurther modifications, and that numerous alternative elements could beemployed, Within the scope of the invention, to perform similarfunctions. The embodiment, in Fig. 5, of three apertures of similardiameter for maintaining constant aperture diameter while varyingshutter speed, could, for example, be modified to show a singleslot-like aperture encompassing said three apertures and the areastherebetween. Instead of the plurality of rebound springs shown in Fig.5, a single rebound spring could be mounted upon a suitable portion ofmember 256, said spring being rotatable to various angular positions asshown in Fig. 1. A further modification of Fig. 5 would comprise anelongated form of rebound spring, said spring tending to spring inwardlyinto the path of shutter rotation and having portions suitably formedfor direct actuation in and out of said path by the cam. It will also beapparent that diaphragm apertures of Fig. 5 could all be of differentdiameter. Rebound springs of various form may be employed as, forexample, one or more rebound springs having incorporated or associatedtherewith means for varying their deflection characteristics and thusvarying shutter speed. Means for altering operational length of aflattype spring would fall within this category. If preferred, therebound spring could be incorporated with the shutter per se, in whichinstance rigid l-ug members, positionable within a plurality ofrelatively slow shutter speeds.

, ferred.

the path of shutter rotation, would serve as reversing means. It willlikewise be apparent that means may be provided for varying tension ofextension spring 92 of Fig. 1 whereby rotational speed of impulse armand, accordingly, of the shutter may be varied, said means, for example,being adapted to adjustments of shutter speed during assembly or havinga control associated therewith for obtaining operational ad.- justmentsof shutter speed.

Where shown, as an element for providing the slowest shutter speed, therebound spring may be supplanted by alternative means for reversingdirection of shutter rotation, said means comprising either hairspringI36 or a hairspring having different torsional characteristicstherefrom. Furthermore, a hairspring having means associated therewithfor varying torsional characteristics thereof could be employed toprovide As shown in Fig. 1, hairspring 43 3 primarily performs thefunction of returning the shutter to closed position after a timeexposure, and, secondarily, that of biasing the shutter toward saidposition should actuating means for an instantaneous exposure fail toaccomplish said movement. It will be apparent that another form of meansfor efiecting return of the shutter to closed position after a bulbexposure may, for

example, comprise a shutter actuating element associated with the bulbexposure latching means per se. The hairspring may thus be eliminatedfrom the mechanism under certain of the above conditions, although itsinclusion is pre- The shutter element may be modified in form as, forexample, by eliminating the counterbalance portion thereoi, saidmodification reducing the mass of the shutter and permitting a lighterconstruction of spring and other associated elements or enabling greaterrotational speed of the shutter.

Since certain changes may be made in the above apparatus withoutdeparting from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of different diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartingrotation to said shutter, means for varying the extent of rotationalmovement of said shutter and thereby varyin exposure time, and commonmeans for rotating said diaphragm to alter the position of saiddiaphragm apertures and for actuating said means varying exposure time.

2. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of difierent diameter placed therein for'rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartingrotation to said shutter, means for varying the extent of rotationalmovement of said shutter and thereby varying exposure time, common meansfor rotating said diaphragm to alter the position of said diaphragmapertures and for actuating said means varying exposure time, and meansreleasably holding said diaphragm apertures and said means varyingexposure time at any of a plurality of correlated settings providingpredetermined exposure values.

3. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of difierent diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartingrotation to said shutter, means for varying the extent of rotationalmovement of said shutter and thereby varying exposure time, common meansfor rotating said diaphragm to alter the position of said diaphragmapertures and for actuating said means varying exposure time, and singlemeans for visibly indicating the aforesaid correlated settings of saiddiaphragm apertures and said means varying exposure time.

4. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of different diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartingrotation to said shutter, means for varying the extent of rotationalmovement of said shutter and thereby varying exposure time, common meansfor rotating said diaphragm to alter the position of said diaphragmapertures and for actuating said means varying exposure time, and commonmeans releasably holding said diaphragm apertures and said means varyingexposure time at any of a plurality of correlated settings providingpredetermined ex- ;posure values.

5. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprisingmeans for rotating said diaphragm to alter the position of saiddiaphragm apertures and for providing variation in the position of saidmeans varying exposure time, means releasably holding said diaphragmapertures and said means varying exposure time at any of a plurality ofcorrelated settings providing predetermined exposure values, and singlemeans for visibly indicating'the aioresaid correlated settings of said16 diaphragm apertures and said means varying exposure time.

6. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of difierent diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means disconnectablefrom said shutter for initiating rotation thereof, said shutter beingadapted to continued rotation after removal of said means for initiatingrotation from contact therewith, variably positionable means foraltering the extent of rotational movement of said shutter and therebyvarying exposure time, common means for rotating said diaphragm to altarthe position of said diaphragm apertures and for providing variation inthe position of said means varying exposure time, means releasablyholding said diaphragm apertures and said means varying exposure time atany of a plurality of correlated settings providing predeterminedexposure values, and single means for visibly indicating the aforesaidcorrelated settings of said diaphragm apertures and said means varyingexposure time.

'7. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of different diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position,

means for imparting rotation to said shutter, means for varying theextent of rotational movement of said shutter and thereby varyingexposure time, means comprising a portion of said diaphragm,simultaneously rotatable therewith, for actuating said last-named meansfor varying exposure time, single control means for rotating saiddiaphragm to alter the position of said diaphragm apertures and actuatesaid means for varying exposure time, and means releasably holding saiddiaphragm at predetermined angles of rotation, said angles providingcorrelated operational settings of said diaphragm apertures and saidmeans for varying exposure time, said settings providing predeterminedexposure values.

8. In a camera, apparatus for providing a photographic exposurecomprising, in combina- .tion, a rotatable disc-like diaphragmcomprising a plurality of apertures of diiferent diameter placed thereinfor rotation to and from operative relation with the exposure apertureof said camera, a rotary shutter element providing a closure for saidexposure aperture when at a stationary position and providing an openaperture during displacement from said stationary position, means forimparting rotation to said shutter, means for varying the extent ofrotational movement of said shutter and thereby varying exposure time,common means for rotating said diaphragm to alter the position of saiddiaphragm apertures and for actuating said means varying exposure time,and single means for visibly indicating theaforesaid correlated settingsof said diaphragm apertures and said means varying exposure time, saidindicating means comprising indicia representing predetermined lightvalues carried. by the diaphragm, said indicia being visiblypositionable with respect to a fixed index.

9. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of different diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartinrotation to said shutter, means comprising a resilient element variablypositionable in the path of rotation of the shutter for rever. ing thedirection of rotation of said shutter, thereby altering the extent ofrotational movement of said shutter and varying exposure time, andcommon means for rotating said diaphragm to alter the position of saiddiaphragm apertures and for actuating said means varying exposure time.

10. In a camera, apparatus for providing a photographic exposurecomprising, in combination, a rotatable disc-like diaphragm comprising aplurality of apertures of different diameter placed therein for rotationto and from operative relation with the exposure aperture of saidcamera, a rotary shutter element providing a closure for said exposureaperture when at a stationary position and providing an open apertureduring displacement from said stationary position, means for impartingrotation to said shutter, means comprising a spring-like element and acam follower associated therewith, said spring-like element beingvariably positionable in the path of rotation of the shutter forreversing the direction of rotation of said shutter, thereby alteringthe extent of rotational movement of said shutter and varying exposuretime, means comprising a tional settings of said diaphragm apertures andsaid means for varying exposure time, said settings providingpredetermined exposure values.

11. Shutter mechanism for association with the exposure aperture of acamera, said mechanism comprising, in combination, a shutter elementproviding a closure for said aperture when at a stationary position andproviding an open ape ture during displacement from said stationaryposition, means cooperating with said shutter element to control themovement thereof, said last-named control means being capable of beingset to a plurality of difierent positions, in one position thereofproviding for one exposure speed and in a second position thereofproviding for a different exposure speed, means for controlling theeffective exposure area of said exposure aperture, said means beingcapable of being set to a plurality of positions and in one positionproviding an eiiective exposure aperture of one area and in anotherexposure position providing for an eiiective exposure aperture in adiflerent area, and common means for controlling the settings of saidaforementioned exposure speed and exposure opening control means so thateach of said two aforementioned shutter speeds may be used inconjunction with at least one of said effective exposure apertures byoperation of said common means.

MURRY N. FAIRBANK.

No references cited.

Certificate of Correction Patent No. 2,504,312 April 18, 1950 MURRY N.FAIRBANK It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 4, line 39, after shutter insert a comma; column 6, line 32, forliimt read limit; column 10, line 13, for of frame read orframe; column12, line 3, after the Word and comma diaphragm, insert and;

and that the said Letters Patent should be read With these correctionstherein that the same may conform to the record of the case in thePatent Oflice.

Signed and sealed this 12th day of September, A. D. 1950.

THOMAS F. MURPHY,

Assistant (J'ommissz'oner of Patents.

Certificate of Correction Patent No. 2,504,312 April 18, 1950 MURRY N.FAIRBANK It is hereby certified that errors appear in the printedspecification of the above numbered patentrequiring correctlon asfollows:

Column 4, line 39, after shutter insert a comma; column 6, line 32, forliimt read limit; column 10, line 13, for of frame read orframe; column12, line 3, after the Word and comma diaphragm, insert and;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case 111 thePatent Oflice.

Signed and sealed this 12th day of September, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant Com/mz'ssioner of Patents.

(Jertificate of Correction Patent NO. 2,504,312 April 18, 1950 MURRY N.FAIRBANK It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 4, line 39, after shutter insert a comma; column 6, line 32, forliimt read limit; column 10, line 13, for of frame read orfmme; column12, line 3, after the Word and comma diaphragm, insert and;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 12th day of September, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

